Rails 4.2 template with active admin, devise, pundit, bootstrap, slim, unicorn, pg (optional), git

rails_4.2_default.rb

# Use with `rails new -m https://gist.githubusercontent.com/sepastian/8d9bf523d3950d4c8a4d/raw/88fd29455af48f5d99569063a6239b5dcdac3d96/rails_4.2_default.rb -d postgresql`

require 'fileutils'

if Rails.version !~ /\A4\.2/
  puts "Required: Rails 4.2.x; found: Rails #{Rails.version}."
  puts "$ bundle update rails"
  exit 2
end

# Rails 4.2 application with:
gem 'bootstrap-sass', '~> 3.3.3'
gem 'sass-rails'
gem 'slim-rails'
gem 'unicorn'
gem 'rails_layout'
gem 'activeadmin', :github => 'activeadmin'
gem 'pundit'
gem 'pg'
gem 'therubyracer', :platforms => :ruby
gem 'devise'
gem 'devise-i18n'
gem 'rails-i18n'
# Cleanup Gemfile, remove blank lines and comments.
gsub_file 'Gemfile', /gem 'sqlite3'/, ''
lines = File.read('Gemfile').split("\n").reject{ |l| l.strip =~ /^\s*\#/ or l.blank? }
remove_file 'Gemfile'
create_file 'Gemfile' do
  lines.join("\n")
end
run 'bundle install'

##
# Database
#
# When using '-d postgresql', the databases APPNAME_development, APPNAME_test and APPNAME_production
# will be created; the users 'rails_unprivileged' and 'rails_privileged' must be created with the
# permission to create databases.
db_adapter = options['database']
use_postgresql = db_adapter == 'postgresql'
exit if db_adapter == 'sqlite3' and no? "Are you sure you want to use #{db_adapter} as a database adapter? [nY]"
if db_adapter == 'postgresql'
  db_name = app_name.underscore
  say 'Updating config/database.yml for PostgreSQL.'
  remove_file 'config/database.yml'
  create_file 'config/database.yml' do <<-END.strip_heredoc
    default: &default
      adapter: postgresql
      encoding: unicode
      password: rails_unprivileged
      username: rails_unprivileged
      pool: 5
    development:
      <<: *default
      database: #{db_name}_development
    test:
      <<: *default
      database: #{db_name}_test
    production:
      <<: *default
      database: #{db_name}_production
      username: rails_privileged
      password: <%= ENV['#{db_name.upcase}_DATABASE_PASSWORD'] %>
    END
  end
end
rake('db:migrate')

##
# Bootstrap
generate("layout:install", "bootstrap3")

##
# Activeadmin
generate("active_admin:install", "AdminUser")

##
# Pundit
FileUtils.mkdir_p Pathname.new('app').join('policies')

##
# Git
after_bundle do 
  git :init
  git :add => '.'
end